1. Field of the Invention
This invention relates to a fluid tight seal which is particularly adapted for use when the direction of applied pressure across the seal alternates.
2. Description of the Prior Art
Under certain conditions it is desirable to perfect a seal between two surfaces that have fluid under pressure present therebetween with the pressure applied first in one direction and then in the opposite direction. An example of such conditions is the seal required for the door of a sterilizing chamber that operates under positive pressure during part of the sterilizing cycle and under vacuum during another part of the cycle.
Typically, the sealing devices used to seal the doors of sterilizing chambers are compression-type devices that depend for their efficacy on being crushed between the sterilizer door and the doorjamb. Such devices, though effective, are subject to wear upon each opening and closing of the door and eventually require repair or replacement. It would be desirable, therefore, to provide a sealing device that would be effective when the applied pressure across the seal alternates, yet would not depend on the application of mechanical compression forces between the surfaces to be sealed for its sealing properties.